1 /* 2 * Generic HDLC support routines for Linux 3 * 4 * Copyright (C) 1999-2005 Krzysztof Halasa <[email protected]> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of version 2 of the GNU General Public License 8 * as published by the Free Software Foundation. 9 */ 10 11 #ifndef __HDLC_H 12 #define __HDLC_H 13 14 15 #define HDLC_MAX_MTU 1500 /* Ethernet 1500 bytes */ 16 #if 0 17 #define HDLC_MAX_MRU (HDLC_MAX_MTU + 10 + 14 + 4) /* for ETH+VLAN over FR */ 18 #else 19 #define HDLC_MAX_MRU 1600 /* as required for FR network */ 20 #endif 21 22 23 #ifdef __KERNEL__ 24 25 #include <linux/skbuff.h> 26 #include <linux/netdevice.h> 27 #include <linux/hdlc/ioctl.h> 28 29 30 /* Used by all network devices here, pointed to by netdev_priv(dev) */ 31 struct hdlc_device_desc { 32 int (*netif_rx)(struct sk_buff *skb); 33 struct net_device_stats stats; 34 }; 35 36 /* This structure is a private property of HDLC protocols. 37 Hardware drivers have no interest here */ 38 39 struct hdlc_proto { 40 int (*open)(struct net_device *dev); 41 void (*close)(struct net_device *dev); 42 void (*start)(struct net_device *dev); /* if open & DCD */ 43 void (*stop)(struct net_device *dev); /* if open & !DCD */ 44 void (*detach)(struct net_device *dev); 45 int (*ioctl)(struct net_device *dev, struct ifreq *ifr); 46 __be16 (*type_trans)(struct sk_buff *skb, struct net_device *dev); 47 struct module *module; 48 struct hdlc_proto *next; /* next protocol in the list */ 49 }; 50 51 52 typedef struct hdlc_device { 53 /* used by HDLC layer to take control over HDLC device from hw driver*/ 54 int (*attach)(struct net_device *dev, 55 unsigned short encoding, unsigned short parity); 56 57 /* hardware driver must handle this instead of dev->hard_start_xmit */ 58 int (*xmit)(struct sk_buff *skb, struct net_device *dev); 59 60 /* Things below are for HDLC layer internal use only */ 61 const struct hdlc_proto *proto; 62 int carrier; 63 int open; 64 spinlock_t state_lock; 65 void *state; 66 void *priv; 67 }hdlc_device; 68 69 70 71 /* Exported from hdlc module */ 72 73 /* Called by hardware driver when a user requests HDLC service */ 74 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 75 76 /* Must be used by hardware driver on module startup/exit */ 77 #define register_hdlc_device(dev) register_netdev(dev) 78 void unregister_hdlc_device(struct net_device *dev); 79 80 81 void register_hdlc_protocol(struct hdlc_proto *proto); 82 void unregister_hdlc_protocol(struct hdlc_proto *proto); 83 84 struct net_device *alloc_hdlcdev(void *priv); 85 86 87 static __inline__ struct hdlc_device_desc* dev_to_desc(struct net_device *dev) 88 { 89 return netdev_priv(dev); 90 } 91 92 static __inline__ hdlc_device* dev_to_hdlc(struct net_device *dev) 93 { 94 return netdev_priv(dev) + sizeof(struct hdlc_device_desc); 95 } 96 97 98 static __inline__ void debug_frame(const struct sk_buff *skb) 99 { 100 int i; 101 102 for (i=0; i < skb->len; i++) { 103 if (i == 100) { 104 printk("...\n"); 105 return; 106 } 107 printk(" %02X", skb->data[i]); 108 } 109 printk("\n"); 110 } 111 112 113 /* Must be called by hardware driver when HDLC device is being opened */ 114 int hdlc_open(struct net_device *dev); 115 /* Must be called by hardware driver when HDLC device is being closed */ 116 void hdlc_close(struct net_device *dev); 117 118 int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, 119 int (*rx)(struct sk_buff *skb), size_t size); 120 /* May be used by hardware driver to gain control over HDLC device */ 121 void detach_hdlc_protocol(struct net_device *dev); 122 123 static __inline__ struct net_device_stats *hdlc_stats(struct net_device *dev) 124 { 125 return &dev_to_desc(dev)->stats; 126 } 127 128 129 static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb, 130 struct net_device *dev) 131 { 132 hdlc_device *hdlc = dev_to_hdlc(dev); 133 134 skb->dev = dev; 135 skb_reset_mac_header(skb); 136 137 if (hdlc->proto->type_trans) 138 return hdlc->proto->type_trans(skb, dev); 139 else 140 return htons(ETH_P_HDLC); 141 } 142 143 #endif /* __KERNEL */ 144 #endif /* __HDLC_H */ 145